This project will develop a novel class of oxygen binding proteins (H-NOX proteins) as a topical treatment for chronic wounds. These proteins are designed to penetrate deep into wounds, deliver oxygen, and improve wound healing. Chronic wounds (wounds that fail to heal over more than 8 weeks) are a significant medical problem and an issue that specifically affects a growing population including the obese, diabetics, and immune compromised patients. Oxygen has a number of important roles in wound healing and clinical studies have shown that increasing oxygen in wounds can accelerate wound healing. A clinically beneficial oxygen delivery system utilizing a topical protein solution could improve clinical outcomes for millions of patients, improving the effectiveness of standard wound therapy and reducing the costs associated with the treatment of chronic wounds and their consequences. The H-NOX proteins (for heme-nitric oxide binding proteins) are a revolutionary oxygen delivery technology discovered and developed at UC Berkeley and exclusively licensed to Omniox. Preliminary data suggest H-NOX proteins successfully oxygenate ischemic tissue. In this project, the H-NOX proteins will be tested as a topical treatment to improve wound healing in two mouse wound models. First, H-NOX proteins will be optimized to deliver oxygen to the low oxygen environment of a hypoxic mouse skin wound. Then, H-NOX proteins will be tested in a mouse model for diabetic wounds to show (1) that H-NOX proteins penetrate deep into the wound tissue to oxygenate the wound and the tissue surrounding the wound and (2) H-NOX proteins improve the processes of granularization and vascularization in the wounds and, most importantly, accelerate overall wound healing in the mouse model of slow-healing diabetic wounds. Demonstration of improved mouse wound healing due to H-NOX oxygen delivery proteins will be the foundation for early clinical development of H-NOX proteins for human wound healing. An H- NOX oxygen delivery solution that could be applied topically to human wounds, deliver oxygen, and improve healing would be an important development for patients and caregivers who manage the significant clinical and quality-of-life burden of treating slow-healing chronic wounds. PUBLIC HEALTH RELEVANCE: This project will use a breakthrough oxygen delivery technology to increase oxygen in wounds and improve wound healing. We will demonstrate that novel oxygen delivery proteins can deliver oxygen to wounded tissue and also penetrate deep into wound tissue and accelerate wound healing. The ability to apply protein to wounds and enhance wound healing will have a significant therapeutic impact for the millions of patients who suffer chronic, slow healing wounds.